Many of these defensive/tactical classes are a few days long. Is anyone so stupid as to believe a person with well-developed, demonstrably higher skill such as this couldn’t absorb that knowledge as well or better than anyone else taking such a class, especially compared to the novice-level shooters in attendance at such classes?

What makes you certain this or any other competitive shooter hasn’t already learned and studied such skills? Just because a specific tactical idea wasn’t tested or demonstrated in a specific range exercise or competitive event doesn’t mean the competitors aren’t aware of them.